Plasmons are quasiparticles resulting from the quantization of plasma oscillations, just as photons and phonons are quantizations of light and sound waves, respectively. Surface plasmons are those plasmons that are confined to surfaces and that interact strongly with light. They occur at the interface of a vacuum or material with a positive dielectric constant with that of a negative dielectric constant (usually a highly conductive material such as a conductive or doped dielectric).
Plasmonics is a field where one exploits the short wavelength of a surface plasmon in an analogous method as one exploits an optical wavelength for information transfer or data manipulation. But, rather than a quantum of light (a photon), a plasmon (collective excitation in electron density) is used.
Plasmons have also been proposed as a means of high-resolution lithography and microscopy due to their extremely small wavelengths. Both of these applications have seen successful demonstrations in the lab environment. Finally, Surface plasmons also have the unique capacity to confine light to very small dimensions which could enable many new applications.
Additionally, plasmons have been considered as a means of transmitting information on computer chips, since plasmons can support much higher frequencies (into the 100 THz range, while conventional wires become very lossy in the tens of GHz). But for plasmon-based electronics to be useful, a device that allows for control of the propagation (or non-propagation) of surface plasmons to accomplish logic functions must be invented.
In view of the above, it in an object of the present invention to provide a plasmonic logic device. Another object of the present invention is to provide a plasmonic logic device that does not require the surface plasmon to be sustained over a long distance (i.e. on the order of a cm or more). Yet another object of the present invention to provide a plasmonic logic device, wherein the surface plasmon wavelength is shorter than light, so that the effective active area of the device can be smaller than prior art logic devices. Still another object of the present invention is to provide a plasmonic logic device that can be fabricated using existing complementary-metal-oxide-semiconductor (CMOS) technology. Another object of the invention is to provide a plasmonic logic device that may operates at high speeds and at low power. Another object of the present invention is to provide a plasmon logic device that manipulates propagation/non-propagation of the surface plasmon to accomplish the basic AND, OR, NAND, NOR, XOR, or NOT Boolean logic functions.